Exam 1 - Treatment of CNS Infections Flashcards
(39 cards)
What type of infections are the following:
- meningitis
- meningoencephalitis
- encephalitis
- brain and meningeal abcesses
- shunt infections
CNS Infections
In bacterial meningitis, where does the organism attach?
Organism attaches to epithelial cells of the NASOPHARYNGEAL or OROPHARYNGEAL mucosa
T/F: Organisms that transmit bacterial meningitis are encapsulated.
TRUE - capsule is a polyprotein that surrounds organism and evades host defenses
Why don’t macrophages try to phagocytize organisms that cause bacterial meningitis?
Because of the capsule that surrounds the organism
When bacteria evade host defenses, what do they cause?
Bacteremia
The Leptomeninges are made up of what two structures?
1) Pia mater
2) Arachnoids
What tissue/structure lies directly over the brain tissue?
PIA MATER
What is the name of the middle layer between the dura mater and pia mater?
ARACHNOIDS
Where is the subarachnoid space (SAS) located?
Between the pia mater and arachanoids
What serves as a conduit for CSF?
SAS
Meningitis is an infection of the ______.
Meningitis is an infection of the SAS.
What values are obtained in a lumbar puncture?
- Glucose
- Protein
- WBC
- Lactic acid
- pH
T/F: Bacteria which lack polysaccharide capsule are incapable of producing meningitis.
TRUE - unless its an open head injury
Name the s/s that a patient with meningitis might present with.
- Fever, stiff neck, or back
- Nuchal rigidity
- (+) Brudzinski sign
- (+) Kernig sign
All lead to seizures and/or hydroencephalus
What are the diagnostic procedures for meningitis?
- Cultures
- Physical exam
- CT scan (looking for hydroencephalus) and MRI imaging
Need meds before doing diagnostic tests
Name the factors that affect antibiotic transfer into the CNS.
- Small molecular weight (Vancomycin has a large molecular weight)
- Antibiotics which are un-ionized (ionization stops it)
- Highly lipid soluble (Aminoglycosides don’t cross the BBB because they are hydrophilic)
- Low protein binding (unbound part interacts with organism)
- Relationship between MBC and concentration in the CSF (should be ~8:1)
Which causative organism is most common in children and young adults in the winter or spring?
Neisseria meningitidis (Meningococcus)
What is the source of Neisseria meningitidis (Meningococcus)?
An asymptomatic carrier
Name the five serotypes responsible for Neisseria meningitidis.
A, B, C, Y, and W-135
Why do 50% of patients die within the first 24 hours of Neisseria meningitidis infection?
Because of its fulminant course - occurs suddenly and escalates quickly
What is the primary clue that the underlying pathogen is N. meningitis?
Presence of petechiae
-50% of patients will present with either purpuric lesions, petechiae, or both
Which organism can have patients that present with a subclinical picture of DIC (Disseminated Intravascular Coagulopathy) with elevated PT and PTT and thrombocytopenia, and elevated fibrinogen and fibrin factors?
Neiserria meningitis
Name the treatment for Neisseria meningitis.
Immediate intervention with Cefotaxime (Kids) 2 g IV Q4H OR Ceftriaxone (Adults) 2 g IV Q12H
T/F: Close contacts of patients with N. meningitidis are at an increased risk of contracting the disease.
TRUE - secondary cases usually develop within 30 days of contact with the index case
